# Tag Info

### Explanation of Quadcopter Dynamics, Components and Control

A couple things, the first is that the controller does not really care what the "real" values are. Everything is relative, if the controller sees that it is sinking it will increase the thrust until ...
• 1,919
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### Using brushless motors for very high torque

Your expectations are rather aggressive for a DC motor. First - 40Nm (350in-lbs) is A LOT of torque! Ex: A max rated torque for 1/4-20 bolt is only 75 in-lb (8.5Nm). Second - The mechanical power ...
• 725

### What are some ways to estimate torque/load on a robotic arm joint

Model Based: Low cost solution is always software: Develop a dynamic model which computes the load on the motors based on the motions (e.g. with Recursive Newton Euler Algorithm or Lagrange-Euler ...
• 6,682
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### How to control ESC from Arduino?

There are quite a few issues I see with your setup. You are setting up the ESC in your code to use pin 9, but your diagram shows that you've connected to pin 8. Pin 8 won't do anything because the ...
• 15.9k
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### Will increasing voltage on brushless DC motor increase torque, if speed is kept constant?

It depends on various other factors as well. If the motor outputs 60RPM @24V under load, given the motor is rated for 12V - 60V and the load is kept the same, then by doubling the voltage from 24V to ...
• 71
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### What is the typical weight distribution for a brushless motor?

I took apart a Turnigy D2836 brushless DC motor. Despite the weight listed on the website, the actual weight of the motor without the mounting equipment is 54 Grams. Here is the breakdown Magnets: 9 ...
• 195

### Can i use DC Brushed motors for building a drone?

I would definitely look at a brushed motor when the budget is low. They have a reputation of being less powerful, but the main problem is they have a very high RPM. This means you either have to use ...

### Electronic Speed Controller

It depends on the voltage. Say you are running 12V: 1820W / 12V = 151A With a 24V system: 1820W / 24 = 75A
Accepted

### Do mobile robots use variable transmissions?

For a simple answer: no, most mobile robots do not use variable transmissions. I believe it is far easier to just design a motor and gearbox combination that works well in your narrow range of ...
• 5,865

### How to avoid oscillations caused by backlash in position control?

Backlash is only an issue when you change directions, because that's when you'll open the space in the gear train. If you're using PID control, consider an overdamped response instead of a typical &...
• 15.9k

### How to calculate the current consumed by a brushless motor on a quadcopter

n = Kv * Vin only when there is no load on the motor. When there is a load on the motor, like from a propeller, you will need to be a bit more clever. For a DC motor (which BLDC motors approximate by ...
Accepted

### Bldc motors erratic behavior with Arduino program

Can you make a written description (comments, text, or block diagram) of what you think the code is supposed to be doing? I can't figure out what your whole timer scheme is supposed to do. Here's ...
• 15.9k

### How to find Friction or Viscous force b (nmsec) in DC motor

When no other load is on the motor, any torque that the motor is producing is to overcome the friction. If you know how to calculate your friction from the torque needed to overcome it (I don't), then ...
• 331

### Why the bldc motor not able to move my water boat?

It sounds to me like you've got cavitation. Basically, the blades are turning so fast that the water around the blades boils. Boiling can happen at normal pressure and high temperature, like on a ...
• 15.9k
Accepted

### Confirm my understanding on BLDC motors

Now if i power the ESC with 48V instead of 16V and set it to 33% instead of 100% The effective voltage on the motor is still 16V and the motor will still use 48W, but since the ESC is getting 48V it ...
• 4,445
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### Is a larger Kv equivalent to more voltage?

OK so lets start with Please correct me if I'm wrong As I understand, a brushless motor has a maximum torque and power (Watts), if you push it beyond its limits ...
• 725

### Explanation of Quadcopter Dynamics, Components and Control

You're right. You should know the rpm of your propellers to build a mathematical model of your quadcopter and if you already have a mathematical model of your brushless DC motors you could compute ...
• 121

### Are all drone propellers compatible with all brushless motors?

Not at all. It is about efficiency, agility, and maneuverability of your drone. Just like wheels on a car, the size of the propeller needs to be matched to the rest of the power system. For ...
• 96

### Is it uncommon to use a gearbox with a brushless motor?

Yes, brushless and grearbox is a normal usecase. Due to the popular application of using brushless motors on drone propellers other applications are harder to find. The keywords "Brushless ...
• 6,682
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### wheeled vehicle forward velocity from RPM brushless data

This project does exactly that on an RC car. The author is a top competitor in the DIYRobocars community; it's the blue car in this video. He uses tachometry from the brushless motor, an IMU and ...
• 356

### DRV8833 Motor driver connected to four raspberrypi zero V1.3 GPIO pins causes motor movement to fluctuate despite setting all pins to OFF

This sounds like you're bringing the chip out of sleep mode before your GPIO pins are set up. Until they are set up, their behaviour will be undefined. The nSLEEP pin is pulled low with a 500k$\Omega$ ...
• 4,263
1 vote

### Driving sensorless three phase BLDC motor with Arduino and IMU

consider coupling the motor with an encoder that has enough resolution to tell you precisely when to ramp up current to a particular phase. this will give you precise feedback to develop a control ...
1 vote

### What are some ways to estimate torque/load on a robotic arm joint

50k4 did a good job of enumerating the different ways to measure torque in the joints. So I won't go into that. But if you want to detect unexpected impacts, another option is to use accelerometers. ...
• 5,865
1 vote

### Vertically moving robot

The most popular method is to use wheel encoders. Since it counts the rpm value, we can maintain the same speed in both sides. But as I understand this is not a reliable way to keep the robot in exact ...
1 vote

### State Space Model of Brushless DC

There is probably no 100% correct/accurate (state space) model. You should consider what is your required precision and use the simplest model which fulfills your accuracy requirements. If you do not ...
• 6,682
1 vote

### DJI E310 Thrust Coefficient

I found a new paper titled "Quadrotor Parameters Identification and Control System Design" (https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7910684) by the same authors published on the ...
1 vote

### Doing a project for college for a manned drone theortically only

Thrust vs. power is not constant -- it depends strongly on prop diameter (bigger diameter = more thrust/watt). It depends less strongly on a bunch of other factors that I would know in detail if I ...
• 1,891
1 vote

### brushless motor as a servo

It's possible, but you need something reading the position of the shaft, since a brushless motor is unaware of its own state. You can use potentiometers, incremental encoders, and absolute angle ...
1 vote

### Using brushless motors for very high torque

R3D34THR4Y, You are on right path. In this video skyentific explains why wide bldc motors are better fit for your problem. He uses OpenTorque Actuator, that was designed and developed by Gabrael ...
1 vote

### Is a larger Kv equivalent to more voltage?

Power is power is power. As you mention in your post, Of course more voltage will reduce the amps but that's not related to the question, I think. Well, it is related to the question, because ...
• 15.9k

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